These species are usually told apart by range, so captive ones can be a bit difficult. There are physical differences but I don't have much experience with this. Maritime Aquarium is out of range for Southern, so if it was a local, wild-caught animal (these usually are) it would be American. Any reason to think it's Southern?
@birdsandbats Back when the aquarium had their amphibian room they kept Southern Toad. I'm not sure how many, if any of their current amphibians came from that room, though.
